The present study is designed to assess the changing risk of homicide among black residents in selected urban environments. Emphasis on changes in risk will be specifically related to the period 1970-75. High risk environments will be identified along with their stressful characteristics. Likewise, the study will utilize a survey instrument to tap a number of economic, social, and psychological characteristics of a sample of offenders, next of kin of victims and next of kin of offenders. The survey items will be employed in explaining causality and measuring impact. Information acquired through the use of the survey instrument will be utilize to test a number of hypotheses relating to black participation in homicidal acts. Among the hypotheses to be pursued are those which treat aspects of the existence of a subculture of violence and the differential propensity of migrants to contribute to the risk of homicide.